## Load lineage and assets from CSV

URL: https://docs.atlan.com/product/capabilities/lineage/how-tos/load-lineage-and-assets-from-csv

> Create lineage and optionally generate assets in Atlan from a source-to-target CSV mapping file stored in Amazon S3. The Lineage and asset loader app reads CSV mappings, creates lineage relationships, and optionally creates missing source or target assets.

Load lineage and optionally create assets in Atlan from a CSV mapping file stored in Amazon S3 using the Lineage and asset loader app. The workflow reads source-to-target CSV mappings, creates lineage relationships between existing assets, and can automatically generate missing source or target assets based on your configuration.

## Prerequisites

- Access to the **Lineage and asset loader** app. Search for it in the Atlan marketplace; if you don't have access, contact [Atlan support](https://docs.atlan.com/support/submit-request) to request it.
- An Atlan connection where lineage process assets live. Create the connection in Atlan before you run the workflow; the workflow doesn't create it.
- A CSV file that follows the required format (one lineage relationship per row). For the exact columns and examples, see the [Lineage and asset loader reference](https://docs.atlan.com/llms/catalog/lineage/lineage-asset-loader/llms.txt).

## Prepare mapping file and S3 access

1. Build your CSV with one row per source-to-target lineage relationship. Include at least **Source Type**, **Source Conn**, **Target Type**, **Target Conn**, **Create Source If Not Exists**, and **Create Target If Not Exists**. For database assets, include **Source DB**, **Source Schema**, **Source Table** and the matching **Target** columns. Use the [Lineage and asset loader reference](https://docs.atlan.com/llms/catalog/lineage/lineage-asset-loader/llms.txt) for the full schema and examples.

2. Upload the CSV to an S3 bucket. Note the bucket name, the full path (key) to the file (for example, `lineage/mappings/etl-to-warehouse.csv`), and the AWS region (for example, `us-east-1`).

3. Create an IAM user that can read from this bucket:
 - In the [AWS Identity and Access Management console](https://docs.aws.amazon.com/IAM/latest/UserGuide/), create a new user.
 - On **Set permissions**, attach a policy that grants read access to your S3 bucket (and the object key prefix where the file lives).
 - After the user is created, create an access key and copy the **Access key ID** and **Secret access key**. You enter these in the workflow.

## Configure and run workflow

4. In Atlan, go to the homepage and click **New workflow** in the top navigation bar.

5. Search for **Lineage and asset loader** and select **Set up workflow**.

6. In **Workflow name**, enter a descriptive name (for example, `prod-etl-lineage-loader`).

7. Under **Input**, select **S3 Bucket**. Enter:
 - **AWS Access Key** and **AWS Access Secret** (the IAM user credentials from step 3).
 - **S3 Bucket Name** (the bucket that contains your CSV).
 - **Mapping filename / key** (the full path to the CSV, for example `lineage/mappings/etl-to-warehouse.csv`).
 - **S3 Region** (for example, `us-east-1`).

8. In **Connection QN**, enter the qualified name of the connection where lineage process assets are created. You can copy this from the connection’s **qualifiedName** in Atlan.

9. In **Name**, enter the name of the custom metadata set the workflow uses to tag managed assets. If it doesn’t exist, the workflow creates and locks it.

10. In **Instance name**, enter the name of the custom metadata property that stores the workflow instance identity (for example, `Loader Instance`).

11. In **Instance unique ID**, enter a unique value for this workflow run (for example, `prod-etl-loader-v1`). The workflow uses this to find assets it created and to deprecate ones no longer in the mapping file.

 Each workflow configuration must use a different **Instance unique ID**. Reusing an ID across configurations can cause the workflow to change or remove assets from another run.

12. Click **Run** to start the workflow.

## Verify results

After the workflow completes:

- In Atlan, search for one of the target assets from your mapping file and open it.
- On the asset, open the **Lineage** tab and confirm the expected upstream and downstream relationships.
- If you used **Create Target If Not Exists** (or **Create Source If Not Exists**), check that the new assets appear in search under the right connection.
- In the asset’s **Custom metadata** panel, confirm the **Instance unique ID** appears on the property you configured.

If lineage is missing for a row, confirm that both source and target assets exist and are active under their connections.

## See also

- [Lineage and asset loader](https://docs.atlan.com/llms/catalog/lineage/lineage-asset-loader/llms.txt): Full configuration reference, CSV schema, and other input methods (object storage, IAM role).
- [Lineage Builder](https://docs.atlan.com/llms/catalog/lineage/lineage-builder/llms.txt): Create lineage from CSV via direct upload or object storage.
- [Build lineage from CSV](https://docs.atlan.com/llms/catalog/lineage/build-lineage-from-csv/llms.txt): How-to for the Lineage Builder app.

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